The invention concerns the air guide box, particularly for a motor vehicle, in which an actuator for an air butterfly valve need not require installation space in the permanently located part of the air box while maintaining a reliable connection with the power source.
Air filter boxes which contain a replaceable air filter insert, for example, should be generally considered as air guide boxes. An air filter box is used in Mercedes-Benz's R 129. Pneumatic butterfly actuating elements for the controllable operation of main air butterflies are held in a part of this air filter box, which is permanently located in a body retention feature and which is essentially used for accepting a replaceable air filter insert for the vehicle passenger compartment ventilation and air conditioning. These actuating elements are located, together with the main air butterflies to which they are mechanically connected by an actuating drive, downstream of the replaceable air filter insert. This accommodation for the actuating elements substantially protects them from environmental effects. Sealing against, in particular, spray water, can be omitted.
A cover part of this air filter box, which is removable for the purpose of fitting a replacement filter insert, is configured as a scoop with air inlet openings. The scoop is sealed against the permanently located part in order to ensure that no air can flow past the filter to the fan and into the internal space of the vehicle. In this arrangement, the pneumatic connecting conduits for the actuating elements can be fixed externally on the permanently located part of the air filter box without difficulty. They must, however, be taken into the internal space of the box at a sealed conduit lead-through.
An arrangement of actuating elements for butterflies of an air guide box on the outside of the box is also shown in DE 38 20 431 A1, but no indication in given of how the connecting conduits of the actuating elements are run. In addition, air guide boxes for heat exchangers are shown in DE 38 36 371 A1 in which the airflow to be guided over the heat exchanger can be throttled to a greater or lesser extent by plates adjustable by a controllable actuator. At high coolant temperatures, the plates are parallel to the flow direction, and during a cold start, they are almost transverse to it and close the air passage in such a way as to achieve rapid heating of the coolant. It is apparent that the part of these air guide boxes covering the heat exchanger and in which the plates are held should be removable without removing the actual heat exchanger carrying the coolant. Also, it should be possible to remove any actuator which may be removed along with the plates.
A motor vehicle heating device located in a casing is shown in DE 33 33 066 C2 in which the heat exchanger is fastened on the inside of the pivotable cover of the casing. The connecting conduits of the heat exchanger are hoses which can be deformed when removing the cover for cleaning purposes and the like. This makes is unnecessary to interrupt the conduit connection.
An object of the present invention is to provide an air guide box with a removable cover part and a permanently located part in such a way that at least one actuator for an air butterfly no longer requires any installation space in the permanently located part of the air guide box while still maintaining its reliable connection to its power source.
The foregoing object has been achieved in accordance with the present invention by fastening the actuating element to the removable cover part of the air guide box, preferably in its internal space for protection against external influences, and supporting the air butterfly in the removable cover part.
Furthermore, in order to avoid having to interrupt specifically the conduit connection between each actuator and its power source, particularly at every removal of the removable cover part, a first section of the conduit is run within the wall of the removable cover part, a second section of the conduit is run within the wall of the permanently located part, and a plug-in connection is provided to connect the two sections of the conduit in the region of the joint between the removable cover part and the permanently located part.
Extensions of the conduit, which respectively provide permanent connection to the power source or to the actuator in the installed condition, are of course connected to the ends of the two sections pointing away from the plug-in connection.
The present invention has the further advantage that although the actuator can still be accommodated in a protected manner within the air guide box, it is accessible when the air box is opened by removing the cover, e.g. for maintenance purposes, and its connection to the power source is interrupted during the same procedure without any special operation being required for this purpose. If the air guide box is closed again, it is impossible to forget to remake the conduit connection because the plug-in connection is necessarily remade during the correct positioning of the removable cover part on the permanently located part. In addition, the problems of leading a continuous conduit into the closed air guide box are avoided from the outset.
Particularly in the case of correspondingly equipped air filter boxed, simple air filter insert replacement or cleaning procedures also remain unimpaired despite the actuator fastened to the movable cover part.
Apart from the differences caused by constructional features, it makes no difference whether an electrical conductor or fluidic conduit connection has to be made to the power source to suit the mode of operation of the actuating element. The power source can be the vehicle electrical system in the case of electrical actuating elements, for example, whereas in the case of pneumatic actuating elements, which are used in the air filter box mentioned, or their hydraulic equivalents, a hose or pipe connection has to be laid to a pump or the like acting as the power source.
It again makes no difference whether the actuating element is fastened to the removable cover part outside the air guide box. The required conduit run in sections in the walls of the air guide box still provides great advantages. Corresponding the above-mentioned DE 33 33 066 C2, it would also be possible with the present invention to use open conduit runs with sufficient excess length to connect the actuating elements. It would then be similarly possible to remove and set down the removable cover part of the air guide box without interrupting the conduit connection but in view of the tight installation space, particularly in motor vehicles, and also for reasons of cost, such excess lengths of conduits are, on the one hand, undesirable and, on the other hand, continually exposed to the danger of damage, e.g. kinking.
In available internal combustion engines, conduits for cooling water and lubricating oil extend between the cylinder block and the cylinder head within the walls of the two parts of the engine and are sealed by the cylinder head gasket in the joint. However, no indication of the arrangement of an actuator in or on an air guide box in accordance with the present invention can be derived therefrom.
An electro-pneumatic actuator shown in DE 36 37 404 C2 has an air conduit for applying alternating pressure to a diaphragm piston is provided through the wall of the two-part casing of the actuator and is similarly sealed in the joint by a flat gasket which penetrates in the region of the conduit. This actuator is in the removable cover part of an air guide box in accordance with the present invention.
Finally, locating a pneumatic coupling in a connecting conduit of a pneumatic locking device in a motor vehicle door in the region of the hinge between the body and the door is shown in DE 37 20 675 A1 and U.S. Pat. No. 2,888,287. This coupling can be released and closed by opening and closing the door. Here again, however, there is no external indication of the arrangement of an actuator on the removable cover part of an air guide box in accordance with the invention or of the proposed conduit run within the box walls.
A dust cap for a fluidic plug-in connection is shown in DE 34 26 089 A1. This cap closed a plug-in opening of the plug-in connection by way of a slit diaphragm after the plug-in connection has been interrupted. When the plug-in part is inserted into the plug-in opening, the plug-in part can be simply introduced through the slit in the diaphragm. This dust cap has no sealing function with respect to the plug-in connection itself and the sealing function is, in fact, undertaken by a separate sealing ring. By using such a dust cap in the plug-in connection of the two sections of the conduit (the dust cap being preferably provide in one piece with a seal for the actual plug-in connection), it is possible in particular in the air filter box application, to prevent dirt particles falling from the insert from penetrating into the conduit section, which extends within the wall of the permanently located box part, during filter insert replacement .